Safety curtain for presses



July 25, 1933. R. A. SHAW 1,919,868

SAFETY CURTAIN FOR PRESSES Filed June 23, 1930 mil INVENTOR ORNEYS Patented July 25, 1933 PAT ROBERT A. SHAW, OF DETROIT, MICHIGAN SAFETY CURTAIN FOR rnnssns Application filedfJnne 23, 1930. Serial No. 463,339.

1' 5 what generally applicable. For example,

the device may be'u'sed upon machines, of press type, that include, in addition to up right frame elements and a fixed or movable platen, a reciprocat'ory'element or elements 10 having a powerful movement of approach relatively to saidplaten; and it is a merit of the present invention that its parts are such as may be either built into machines of the "general type ref'e'rredto or of other 15 types or applied thereto subsequently to manufacture. t

More specifically, it an object of the present invention to provide a curtain or safety gate element, preferably comparative 1y light but substantially rigid, not only with means for elevating same in such a 'manner as to permit a handfeeding operation, when the mentioned reciprocatory element is up, but also with means for lower 'ing the'same during the descent of said refciprocatory element and at a comparatively high rate of movement, to afford warning or otherwise to occasion a due removal of an operatives hands from any position of ens r- 4 O'therobjects of the present invention, in

which the mentioned reciprocatory element may be assumed to be manipulated by means 'r comprising a connecting rod or rods and in il y connected with a connecting rod orrods) maybe best appreciatedfrom the following description ofan illustrative embodiment of the invention, taken connection with the appended claims and the accompanying drawing, l

lisan' elevational'view of a press to which a'n embodiment-of the invention has been applied. P

Fig. 2 is a vertical section,'taken substantially as indicated by the line 2-2 of Fig.1.

Refeii'ingfii'st to the moreconventional features of that embodimentof the present invention which has been selected for purposes of illustration, a one-piece'or other w Oweframe upon a'base may include, in addition -to a horizontal 1 platen or lower connecting element 11 and an arcuate overhead connecting element 12, 'a pair of substantially vertical upright guide elements 13, 13 for a reciprocatory element 14; and saidreciprocatory element is shown as manipulableby means including a crank-shaft 15-,receivedin bearings 16, 16 that may be supported from the mentioned frame by means including a web 12'." Said shaft is shown as including an extension 17, project 'ingthrough the upright frame element 13 V and provided with means, including a large gear 18, for mparting a comparatively slow powerful rotative movement thereto. 'This rotative movement may be transformed into a reciprocatory movement of the element 14-, orits equivalent, by means such as cranks 20,20, provided upon the shaft 15, and connecting rods 21, 21 pivotally connected with said cranks and with said reciprocatory 'eleme1'1t,these being well known features of press-construction.

Coming now to the more novel features of the present invention, a light but rigid curtain element 22 is shown as dependently supported by flexible means including ropes or equivalent linear tensionelements 23, 23 '(which "maybe secured thereto by'ineans such as stapledike U bolts 24,24 ,and the v upper or remote ends of "the fieXiblefelements 23, 23 areintende'ddn all cases to be connected with means for;- imparting thereto a more extensive and more rapid movement of reciprocation-than that which may be imparted to the reciprocatory ele- 'ment 14 through theconnecting rod 'or rods 21, 21 or other meansof manipulation. 1

Forthe purpose'last referred to, an additional pair of tension elements2 5, 25 be- 'ing shown as attached (by means optionally including threaded posts 26, 26 and hooks or rings 27, 27) to the upper ends of the connecting rods 21, 21, like pairs of sheaves, 28, 28 and 29, 29 may advantageously be supported in an out-of-the-way position and at an intermediate level,as by means of shafts 30, 30, supported in brackets 31, 31', the latter being optionally secured to the respective side or guide posts 13,13 above the intended limits of movement of the reciprocatory member 1 1 or out of the path of any guide elements 32, 32 provided thereon.

The described construction will be seen to provide for the dependent support of a light gate of curtain element, such as may be formed from or framed by inexpensive sheet metal, in such manner as to effect a timely upward withdrawal of the same to permit a manual introduction and removal of any articles or materials, constituting the work, from between the platen 11 and the reciprocatory element 14, or any equivalent part; and the ratio of the sheave or sheaves 28, 28 to the sheave or sheaves 29, 29 may be such as to eifect a timely and ample movement of the curtain 22, or its equivalent (a sheave ratio of 1 t0 2 being suggested as suitable) and also such as to assure aprompt descent of said curtain, or its equivalent,- into engagement with the arms of an operative, in case he is dilatory, in time to permit, and/or in such manner as to expedite a Withdrawal thereof before the descent of the reciprocatory element 14: shall be so far completed as to prevent such withdrawal. The lateral positions of the mentioned sheaves and all parts connected therewith will be seen to obviate obstructions t0 the use of the press, or any equivalent machine or unit, in a customary manner.

Obviously the guarded opening may be totally different from that shown; light and dependent or otherwise easily movable curtains or safety gates of the described type may be used with alternative motionmultiplying means; the sheaves constituting a united pair, when sheaves are employed, may have any desired ratio and may be variously spaced apart and disposed, according to conditions involved; and either gravity or spring action may be relied upon yieldably to bring curtains or gates, one or more to a machine, either to or from a safeguarding position relatively to an opening or to moving parts; but the weight and the mode of manipulation of each gate and its relationship to other fixed parts and motionimparting parts are intended always to be such as to give notice or to expedite or obstruct some movement with a view to obviating risk of e. g. pinioning a workers limbs in any position of danger. It it primarily for this last-mentioned reason that flexible means and light materials are employed in its manipulation and construction of the gates, the latter being preferably foraminous or translucent in order to permit the operative to get a clear View of the work at all times.

No duplication of gates at the front and/or rear of a machine or furnace or other unit may ordinarily be required; but it should be noted that a single small sheave may be secured on the same shaft with either one or two or more large sheaves,each connected with one or more ropes running to near or remote gates; and within limits, these sheave organizations and gates may be provided in a series of standardized sizes, to be applied by the purchaser as they may be needed. If desired, each may include a guide eye 33 and/or provide a plurality of alternative bearing openings for shafts 30, 30.

Although the foregoing description has included complete details of but one embodiment of the present invention, it will be understood not only that various features thereof might be independently employed, but also that numerous modifications, additional to any suggested herein, might easily be devised by skilled workers, if informed of the foregoing,all without departure from the scope of the present invention, as the latter is indicated above and in the following claims.

What I claim is:

1. In a hand-fed power-driven machine of press type comprising a platen element disposed between upright frame elements and adapted to cooperate with a reciprocatory element, a safety organization comprising: a curtain element; and means for so reciprocating the same in front of said platen element as to occasion timely withdrawal of an operatives hand from between said platen element and said reciprocatory element,said reciprocatory elementv being movable by means including a pair of connecting rods and said last mentioned means including pairs of sheaves respectively rotatably supported from said upright frame elements, and including also flexible elements extending from said sheaves to said connecting rods and to said curtain element to permit the movement of the curtain element away from said platen element.

2. The combination with a hand-fed power-driven machine of the press type including, in combination, a work receiving table and a ram reciprocable toward and away therefrom, of a guard for said machine, cables supporting said guard, sheaves about which said cables are secured, additional, sheaves secured to said first said sheaves and actuated by cables in accordance with the movement, of said ram, and guides for said cables for retaining said guards in predetermined position and permit said guards to:

. and

multiplying device comprising: a shaft; a

plurality of sheaves differing in size, secured V thereon; and flexible means extending from said sheaves respectively toward a motionimparting member and toward said gate for eflecting a differential movement to said gate, and guides for engaging said flexible members and positioning said gate in such manner as to have the gate freely movable outwardly of said motion-imparting emember.

- ROBERT A. SHAW. 

